Near-field microwave microscopy. Capabilities. Application areas

In this paper we have considered operating principles, presented main characteristics, discussed merits and demerits, shown samples of application of different types of near-field scanning microwave microscopes. We have shown the possibility to utilize low-dimensional microwave resonators based on systems like "pin with gap - nearly placed shorting plug" and "inductive diaphragm - capacitive diaphragm" as a probe in near-field microwave microscope to increase the sensitivity and resolution. The resolution of 0.5 μm has been achieved. The description of near-field microwave microscope based on the semiconductor Gann-diode autodyne oscillator is presented. The probe of the microwave microscope was created on the base on the waveguide-to-microcoaxial adapter with center conductor jutted out of the outer conductor. Using the created autodyne near-field microwave microscope the microwave imaging with high space resolution was demonstrated. The relief and electrophysical properties of the ceramic plate surface with applied metal layer were imaged with both direct access to the scanned object and in the mode of subsurface probing.